Bedroom Environment Research Articles

0078 Subjective but not objective sleep predicts morning motivation to complete more difficult tasks

Abstract Introduction Sleep deprivation impairs many facets of behavior, including performance at tasks. People may perform less efficiently at tasks due to impairments to cognitive processes like working memory following sleep deprivation. However, research shows that compensatory activity occurs when participants are sleep deprived and are faced with difficult tasks (Horne & Pettitt, 1985). This study explored participants’ capability and motivation of completing tasks of varying difficulties. Methods These data come from a larger study investigating bedroom environment, sleep, and cognition. In this study participants were given an actigraph wgt3x and were told to sleep as they normally would for three-day period. Each morning, participants took a brief survey and cognitive battery shortly after waking. In the survey, participants self-reported their sleep quality from the previous night using a modified version of the sleep disturbance subscale from the Medical Outcomes Survey (Hays et al., 2005). Additionally, a modified version of the Math Effort Task (MET; Engle Friedman et al., 2003) was used. Participants chose a difficulty and completed six simple addition problems without aid of a calculator or scratch paper. Data were cleaned and analyzed using generalized linear mixed effect modeling in SPSS 28. Results Two models were run to examine performance (accuracy) and difficulty choice on the MET. In our model predicting performance there were no significant predictors. In our model predicting the choice of difficulty, participants of more socially advantaged populations and those who reported better subjective sleep quality chose to complete harder problems (b = -.05, p = .01). No significant findings were observed between objective measures of sleep such as sleep efficiency and duration with difficulty chosen or performance. Conclusion Motivation to complete more difficult tasks may be related to the quality of sleep one receives during the previous night. The observed lack of difference in performance based on sleep suggest that when given simple problems, sleep deprivation does not impair cognitive performance or that people can compensate for poor sleep when the task is easy. Future studies should continue to explore the relationship between sleep and motivation. Support (if any) I/O small grant department funding, university research funding, and travel funding.

Associations of bedroom PM2.5, CO2, temperature, humidity, and noise with sleep: An observational actigraphy study

ObjectiveClimate change and urbanization increasingly cause extreme conditions hazardous to health. The bedroom environment plays a key role for high-quality sleep. Studies objectively assessing multiple descriptors of the bedroom environment as well as sleep are scarce. MethodsParticulate matter with a particle size <2.5 µm (PM2.5), temperature, humidity, carbon dioxide (CO2), barometric pressure, and noise levels were continuously measured for 14 consecutive days in the bedroom of 62 participants (62.9% female, mean ± SD age: 47.7 ± 13.2 years) who wore a wrist actigraph and completed daily morning surveys and sleep logs. ResultsIn a hierarchical mixed effect model that included all environmental variables and adjusted for elapsed sleep time and multiple demographic and behavioral variables, sleep efficiency calculated for consecutive 1-hour periods decreased in a dose-dependent manner with increasing levels of PM2.5, temperature, CO2, and noise. Sleep efficiency in the highest exposure quintiles was 3.2% (PM2.5, p < .05), 3.4% (temperature, p < .05), 4.0% (CO2, p < .01), and 4.7% (noise, p < .0001) lower compared to the lowest exposure quintiles (all p-values adjusted for multiple testing). Barometric pressure and humidity were not associated with sleep efficiency. Bedroom humidity was associated with subjectively assessed sleepiness and poor sleep quality (both p < .05), but otherwise environmental variables were not statistically significantly associated with actigraphically assessed total sleep time and wake after sleep onset or with subjectively assessed sleep onset latency, sleep quality, and sleepiness. Assessments of bedroom comfort suggest subjective habituation irrespective of exposure levels. ConclusionsThese findings add to a growing body of evidence highlighting the importance of the bedroom environment—beyond the mattress—for high-quality sleep.

Non-contact determination of sleep/wake state in residential environments by neural network learning of microwave radar and electroencephalogram–electrooculogram measurements

This study developed and validated a non-contact, integrated sleep measurement method using microwave radar for daily sleep measurement in a house. In order to replicate the participant's normal sleep as much as possible, we employed a portable electroencephalogram–electrooculogram (EEG–EOG) recording system, which has the lowest burden and established reliability in the bedroom environment. A total of 38 nights of sleep for 15 participants were simultaneously recorded using the portable EEG–EOG recording system, actigraph, and microwave radar in the bedroom of typical houses. The sleep/wake state determination obtained by applying EEG–EOG data to a deep learning-based sleep staging program was used as the target variable. A sleep/wake state determination prediction model was obtained by learning body movement data from microwave radar using a neural network. The inter-method reliability was evaluated using sleep parameters, including sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE), by using paired t-test. Based on this prediction model, the average accuracy, sensitivity, specificity, F1-score*100, and Cohen's kappa*100 for all participants' sleep/wake state determination using microwave radar were 95.27%, 70.11%, 97.05%, 65.95, and 63.46, respectively. Compared with the portable EEG–EOG recording system, microwave radar showed no statistically significant differences in SOL, TST, and SE in evaluating sleep parameters. As the main conclusion, in the sleep/wake state determination, microwave radar showed performance comparable with or better than actigraph. It serves for continuous non-contact sleep measurement in residential environments.

Exploring the effects of spectral light exposure on University students' sleep quality: A cross-sectional study

In developed nations, 2/3 of the population fail to obtain the recommended 7-9 hours of sleep, with large consequences for health and productivity. A potent stimulus in regulating sleep and wake balance is light received at a light-sensitive retinal protein called melanopsin, found in our retinal cells, otherwise known as intrinsically retinal ganglion cells (ipRGCs). Hence, to better understand the effects of bedroom indoor environmental quality IEQ on sleep, we set up a study to objectively explore the impact of spectral light exposure through non-visual pathways on the participants' sleep quality. For one week, University students measured IEQ in their bedrooms while monitoring their spectral light exposure during the day and sleep quality at night. The students were asked to keep the bedroom environment unchanged for the measurement period. Our preliminary results show trends between 7-day accumulative light exposure and length of deep sleep. This trend is not significant, and further in-depth analysis is needed. Among other limitations in the processed data, the diverse and mixed demographic of the sample was not considered. The students' living conditions (single vs. family, accommodation, etc.) varied in this initial analysis.

A Study in Bedroom Living Environment Preferences of the Urban Elderly in China

This study aims to analyze the indoor environment preferences of Chinese urban elderly, to create a living environment that is beneficial to the physical and mental health of Chinese elderly, and to enhance their sense of well-being. Based on an in-depth study of 306 urban elderly’s bedroom indoor environment preference in 21 Chinese provinces, using questionnaire method, this study concludes that: (1) Group characteristics: for urban elderly, the key words for bedroom color and lighting preference are low saturation, bright, warm tones and warm white light; personal characteristics such as the gender, physical condition, and education have a strong correlation with factors in the indoor living environment; (2) Physical environment preferences: gender presents the most significant potential effect on elderly physical environment preferences; (3) Established indicator system: the indicator system includes five main indicators of basic bedroom conditions, bedroom materials, bedroom colors, bedroom physical environment and other soft furnishings, and 22 sub-indicators. This study has some implications for guiding the design of elderly’s apartments and the bedroom environment, as well as effectively using the indoor environment to meet the physiological and psychological needs of the urban elderly.

A cross-sectional field study of bedroom ventilation and sleep quality in Denmark during the heating season

Parameters describing the bedroom environment and sleep quality were measured overnight for one week in 84 randomly selected actual bedrooms in Denmark from September to December 2020. The median age of participants was 26 years (interquartile range (IQR) [24-32] years); 41 were males. Carbon dioxide (CO2), temperature, and relative humidity were measured continuously. Sleep quality was assessed by the Groningen Sleep Quality Scale (GSQS) on two mornings and was assessed using wrist-worn sleep trackers. Skin temperature was monitored continuously. Bedroom indoor air quality (IAQ) was rated by participants on two occasions just before sleep in the evening and upon waking up in the morning. Measurements from 75 bedrooms were complete. The median [IQR] of mean CO2, air temperature and relative humidity measured during sleep were 1,120 [741–4,804] ppm, 23.4 [22.3–24.4]°C, and 48.6 [44.7–55.4]%. The median [IQR] of GSQS was 4.0 [1.0–6.0] suggesting medium to poor subjectively rated sleep quality; the objectively measured sleep efficiency, and percentage of light, deep and REM sleep were in normal ranges: 88.1 [86.1–89.5]%, 59.4 [54.9–64.5]%, 18.3 [15.0–21.7]%, and 23.0 [18.4–26.4]%. The subjectively-assessed sleep quality decreased when perceived IAQ was reduced. Opening the bedroom door or window, which is a proxy for enhanced ventilation, also improved subjectively-assessed sleep quality and IAQ. The cross-sectional nature of the study prompts the validation of the present results with protocols that include measurements of other pollutants besides CO2 as well as the examination of underlying mechanisms. Nevertheless, they strongly suggest that keeping high bedroom IAQ is essential.

Performance of cough monitoring by Albus Home, a contactless and automated system for nocturnal respiratory monitoring at home.

Objective cough frequency is a key clinical end-point but existing wearable monitors are limited to 24-h recordings. Albus Home uses contactless motion, acoustic and environmental sensors to monitor multiple metrics, including respiratory rate and cough without encroaching on patient lifestyle. The aim of this study was to evaluate measurement characteristics of nocturnal cough monitoring by Albus Home compared to manual counts. Adults with respiratory conditions underwent overnight monitoring using Albus Home in their usual bedroom environments. Participants set-up the plug-and-play device themselves. For reference counts, each audio recording was counted by two annotators, and cough defined as explosive phases audio-visually labelled by both. In parallel, recordings were processed by a proprietary Albus system, comprising a deep-learning algorithm with a human screening step for verifying or excluding occasional events that mimic cough. Performance of the Albus system in detecting individual cough events and reporting hourly cough counts was compared against reference counts. 30 nights from 10 subjects comprised 375 hours of recording. Mean±sd coughs per night were 90±76. Coughs per hour ranged from 0 to 129. Albus counts were accurate across hours with high and low cough frequencies, with median sensitivity, specificity, positive predictive value and negative predictive values of 94.8, 100.0, 99.1 and 100.0%, respectively. Agreement between Albus and reference was strong (intra-class correlation coefficient (ICC) 0.99; 95% CI 0.99-0.99; p<0.001) and equivalent to agreement between observers and reference counts (ICC 0.98 and 0.99, respectively). Albus Home provides a unique, contactless and accurate system for cough monitoring, enabling collection of high-quality and potentially clinically relevant longitudinal data.

Design And Development Of A Baby Sleep Monitoring System Based On Internet Of Things (Iot)

A baby's condition during sleep is a condition that requires intense attention directly from the parents. The quality and quantity of baby sleep are very much affected by the conditions and setting of the environment where the baby sleeps, including the baby's space for movement, room temperature, light intensity, sound/noise, and humidity of the room. Keeping the quality of the baby's sleep is very important both for the baby and for parents. The Design and Development of a Baby Sleep Monitoring System Based on the Internet of Things (IoT) aim to help parents monitor their baby while sleeping and optimize the quality of baby's sleep by monitoring the conditions of the baby's bedroom environment without being present in person. Parents can monitor their baby's condition while sleeping by getting alerts to their smartphone if the conditions exceed the threshold of the ideal limits received from the IoT sensors, like sound sensor, movement sensor, temperature, and humidity sensor. Therefore parents can feel serenely in doing their daily activities, and the baby still gets theappropriate sleep needs.

Does knowledge of sleep hygiene recommendations match behaviour in Australian shift workers? A cross-sectional study

ObjectivesShiftworkers routinely obtain inadequate sleep, which has major health consequences. Sleep hygiene describes a range of behaviours, lifestyle and environmental factors that can improve sleep. To date, limited research has...

Objective sleep assessments for healthy people in environmental research: A literature review.

To date, although many studies had focused on the impact of environmental factors on sleep, how to choose the proper assessment method for objective sleep quality was often ignored, especially for healthy subjects in bedroom environment. In order to provide methodological guidance for future research, this paper reviewed the assessments of objective sleep quality applied in environmental researches, compared them from the perspective of accuracy and interference, and statistically analyzed the impact of experimental type and subjects' information on method selection. The review results showed that, in contrast to polysomnography (PSG), the accuracy of actigraphy (ACT), respiratory monitoring-oxygen saturation monitoring (RM-OSM), and electrocardiograph (ECG) could reach up to 97%, 80.38%, and 79.95%, respectively. In terms of sleep staging, PSG and ECG performed the best, ACT the second, and RM-OSM the worst; as compared to single methods, mix methods were more accurate and better at sleep staging. PSG interfered with sleep a great deal, while ECG and ACT could be non-contact, and thus, the least interference with sleep was present. The type of experiment significantly influenced the choice of assessment method (p<0.001), 85.3% of researchers chose PSG in laboratory study while 82.5% ACT in field study; moreover, PSG was often used in a relatively small number of young subjects, while ACT had a wide applicable population. In general, researchers need to pay more attention at selection of assessments in future studies, and this review can be used as a reliable reference for experimental design.

Application potential of skin temperature for sleep-wake classification

It’s well known that skin temperature regularly fluctuates during the sleeping period, but few studies quantitatively analyzed its changed during sleep-awake transformation. In laboratories where the bedroom environment was strictly regulated, 14 subjects (7 males and 7 females) slept for 4 days periodically during 2-month period, and their electroencephalogram (EEG), electrooculogram (EOG) and electrocardiogram (ECG) were record by polysomnography (PSG), to determine the time of falling asleep and waking up. In addition, skin temperatures at seven points (forehead, chest, forearm, hand, thigh, calf and foot) were continuously measured by pyrobutton throughout the whole period. For the purpose of seeking the appropriate judgment index in sleep-wake classification, significant change (p < 0.5), large effect size (Cohen's d greater than 0.8), and relatively small individual difference (C.V < 0.5) were proposed as the selection criteria. The analysis results showed that, change value of skin temperature at single point is not recommended, even if it met partial criteria. The skin temperature gradient has potential to be used as a quantitative index for sleep-wake classification, because it could satisfy the three criteria at the same time. Skin temperature gradients between limbs and chest gradually increased before falling asleep and decreased after waking up. At the moment of falling asleep, the average skin temperature gradients between hand and chest were 1.55 °C in males and 1.84 °C in females, respectively, while between foot and chest were 1.05 °C in males and 1.58 °C in females, respectively. Although the skin temperature gradient at the stage of waking up showed a similar law to that of falling asleep, it needs to be further explored since there are more complex situations.

Data fusion of mobile and environmental sensing devices to understand the effect of the indoor environment on measured and self-reported sleep quality

The Indoor Air Quality (IAQ) of the bedroom environment has recently garnered attention since air pollution can affect sleep. Previous studies investigated IAQ and sleep quality in controlled environments which impacts both self-reported and measured sleep quality. Studies within a participant’s home environment are ecologically valid and reduce participant bias. Here, we study 20 participants over 77 days in Austin, TX. We monitored five components of IAQ using the BEVO Beacon, a calibrated purpose-built environmental monitor, and measured participant sleep quality through wearable activity trackers and 4-question surveys sent four times a week. We found significant decreases in sleep quality during nights with elevated CO, CO2, and temperature. Elevated CO was associated with a mean increase in 0.9 self-reported awakenings and decreases in device-measured sleep time of 21.6 min and sleep efficiency of 0.6%. Increased CO2 and temperature were associated with decreases in device-measured sleep time of 17.5 and 15.2 min, respectively. Elevated PM2.5 and TVOCs concentrations were associated with overall improvements in sleep quality. Participants reported a mean of 4.4 fewer awakenings and had a 1.1% increased in measured sleep efficiency for nights with elevated PM2.5. Elevated TVOCs were associated with an increase in sleep time of 14.5 min. These findings indicate a need to study the relationship between these aggregate IAQ measures and sleep quality more closely. Our results also indicate that pollutants can independently affect sleep quality regardless of the CO2 measurements. Compared to literature, our study is the longest and includes the most IAQ parameters.

Field Measurements of Bedroom Environment in Winter and Summer on Qinghai-Tibet Plateau

Field measurements of the bedroom environment on Qinghai-Tibet Plateau was conducted by continuously measuring the air temperature, relative humidity, and CO2 concentration in the bedrooms of 197 residents (100 in winter and 97 in summer) for 7 days. And the daily environmental controls of residents were recorded. The results showed that the night-time thermal environment in bedrooms on the Qinghai-Tibet Plateau was more warmer and wetter in summer than in winter, but the CO2 concentration was lower in winter. On both winter and summer nights, drops in air temperature, relative humidity and CO2 concentration in the bedrooms were found when doors or windows were opened, increases in relative humidity and CO2 concentration in bedrooms were found when there were more occupants in the bedrooms. This study also found there was a greater reduction of CO2 concentrations when doors or windows were opened in the bedrooms of multiple occupants compared to the bedrooms of a single occupant. And on winter nights, the humidity increase in the bedrooms caused by the action of the humidifier was not affected by the status of doors and windows.

Short-term and long-term associations with sleep onset latency in school children in Japan.

This study aims to examine the relationships between sleep onset latency and multiple sleep-related factors of seventh and tenth graders during the transition from childhood to adolescence. Regarding sleep onset latency, we examined the short-term associations in Phase IV (2002) and long-term associations in Phase V (2005) of the Toyama Birth Cohort Study. In total, 4,673 boys and 4,694 girls in Phase IV and 2,969 boys and 3,108 girls in Phase V answered the questionnaire items regarding sleep, physical and mental health, lifestyle, socioeconomic status, and family and school factors. Considering sleep onset latency as the outcome and 13 sleep-related factors as independent variables, we calculated the odds ratio using binary logistic regression. The longitudinal study was conducted with 1,703 boys and 1,919 girls whose sleep onset latency was within 30 min in Phase IV. The following factors were found to be related to longer sleep onset latency in the short term: sleep duration, physical activity, game time, and self-esteem in boys and sleep duration, bedroom environment, game time, abdominal pain, long-standing illness, onset of puberty, mental health difficulties, and school avoidance feelings in girls. Regarding its long-term effects, having a single parent and self-esteem in boys and breakfast, game time, long-standing illness, obesity, onset of puberty, and school avoidance feelings in girls were associated with longer sleep onset latency. Education of adolescent health and sleep hygiene at home and school should include both short-term and long-term associations between sleep and a healthy lifestyle by gender.

Dimensions of Students’ Satisfaction with Residential Housing and its Impact on their Loyalty – A South African Study

Abstract As an important component of student lifestyle, satisfaction with residential housing has become important in examining student housing quality and services. The current study used five attributes – bedroom environment, building quality, washroom facilities, support services, and leisure room facilities – to examine the relationship between student satisfaction with and loyalty to their residential housing. Each construct was measured using four items on a five-point Likert scale, ranging from 1 ‘Strongly disagree’ to 5 ‘Strongly agree’. The data were collected from South African students aged 18 years and above in tertiary institutions in Johannesburg, using paper-based questionnaires. Four hundred and forty-three (443) usable questionnaires were obtained for the analysis. The results showed that all the attributes, except for the bedroom environment, had a positive and significant relationship with student loyalty to student housing, although the effect was small for all the attributes. The control variables – age and gender – showed a similar relationship in regards to student loyalty. Academic and management implications of this study’s results are also discussed extensively. Overall, students’ satisfaction with residential housing dimensions has a positive and significant impact on their loyalty to the providers of residential housing.

Association of bedroom environment with the sleep quality of elderly subjects in summer: A field measurement in Shanghai, China

Sleep is essential for the health of elderly people, but few studies have made connection between their sleep quality and their bedroom environment. This study performed field measurements in Shanghai, China, to investigate the bedroom thermal environment and ventilation and their associations with the sleep quality of elderly subjects in summer. Forty-five elderly subjects participated in this study for six consecutive days. Their bedroom air temperature, relative humidity and CO2 concentration were measured continuously and their sleep quality was objectively measured using a wrist-worn sleep tracker. Wrist skin temperature was measured continuously at night. Each morning after waking up the subjects assessed their sleep quality, recalled their thermal sensation, and recorded their bed covering, sleepwear and cooling/ventilation arrangements during that night. The results show that higher air temperature and CO2 concentration were both negatively correlated with objective sleep quality. Air temperature was the key factor influencing objective sleep quality. When air temperature increased by 1 °C, sleep efficiency (SE) decreased by 0.7%, duration of Rapid Eye Movement (REM) sleep decreased by 2.1min, and time awake increased by 2.3min. The sleep quality of elderly subjects was more negatively affected by heat exposure than has been previously reported for younger subjects. As CO2 concentration increased by 100 ppm, the Total Sleep Time (TST) decreased by 11min. The combined effects of air temperature, relative humidity and CO2 concentration were analyzed: TST and duration of REM sleep were reduced at higher air temperature, relative humidity and CO2 concentration.

Five hypotheses concerned with bedroom environment and sleep quality: A questionnaire survey in Shanghai city, China

Based on the researches conducted in recent decades, five hypotheses concerned with bedroom environment and sleep quality were proposed. In order to verify these hypotheses, we conducted a questionnaire survey which lasted one year in Shanghai. This questionnaire contained questions on inhabitants' basic information, inhabited environment, living habits and sleep quality. A total of 1130 valid questionnaires (540 males, 590 females) were obtained. Results showed that inhabitants' sleep quality was significantly affected by heat in transitional season, cold, heat and noise in summer, cold, heat, dryness and noise in winter, respectively. People living in the bedrooms without plants had a 74.5% chance of getting better sleep than those living in rooms with plants. Artificial facilities (objects or areas constructed with certain functions) around houses had a significant negative effect on inhabitants' sleep quality, but no significant impact of natural landscape (original landscape of nature) was found. Ventilation was an effective way to improve bedroom environment. The frequency of ventilation in the morning was significantly correlated with sleep quality (p < 0.05), and ventilation time longer than 15 min per day helped significantly improve the inhabitants’ sleep quality (p < 0.05); during sleep period, compared with the inhabitants in sealed bedrooms, the average sleep quality of inhabitants who opened doors increased by 26.0%, 4.7% and 13.9% in transitional season, summer and winter, respectively, but opened windows had no obvious effect. Generally, the five hypotheses were highly or moderately verified, which could play an important guiding role in future studies.

A survey of bedroom ventilation types and the subjective sleep quality associated with them in Danish housing

We performed a survey of the types of bedroom ventilation in Danish dwellings (January–February 2020) and the associated subjective sleep quality. Five hundred and seventeen people responded. Their median age was 33 years old and 55.4% of them were males. We used an online questionnaire and collected information on the type of bedroom ventilation, bedroom airing behaviour by the respondents, the bedroom environment, building surroundings and location, and sleep disturbance caused by stuffy air, noise, and the thermal environment. Subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI); its median among respondents was >5 indicating reduced sleep quality. 35.4% of the bedrooms had mechanical, 24.6% exhaust, and 40.0% natural ventilation. Sleeping in a bedroom with mechanical ventilation tended to reduce sleep disturbance. The absence of mechanical ventilation and the presence of carpet in the bedroom were all associated with stuffy air causing sleep disturbance, which was the second most sleep disturbing factor. PSQI increased significantly with increased sleep disturbance. People who reported that their sleep was disturbed by stuffy air or “too warm” conditions opened windows frequently during the day or night, but no association was found between PSQI and bedroom airing behaviours. Our results are valid for the heating season and the survey would have to be repeated in the non-heating season to permit generalization of the findings. The results present associations and are qualitative, so field measurements are necessary to validate the present observations and provide further explanations.

Impact of Feng Shui Bedrooms on Self-Assessed Sleep and Well-Being: A Randomized Double-Blind Field Research with Instrumental Biocommunication

&#x0D; &#x0D; &#x0D; Chinese feng shui is well-researched in social sciences but under-researched regarding its impact on the well-being of users. The main problem is the isolation of feng shui effects. Participants (n=134) provided a photograph of their bedroom onto which feng shui recommendations were sent long distance (for 4 months), using an instrumental biocommunication device with a computer, white-noise diode and fengshui recommendations database. Three groups were formed, one acted as control (double-blind protocol). Data was collected through self- evaluating questionnaires (n=10) on the quality of sleep and well-being. Data were statistically evaluated with R environment using linear mixed models and the analyses of variables: feng shui support, stress, age and bedroom evaluation. Results for sleep show feng shui as the most statistically significant variable (p=&lt;0.001). For each day the value increases by 0.003 on the Likert scale 1-5. In 120 days, it increases by 0.36. The impact is dynamic and in direct connection with the level of our living environment satisfaction, stress and age. For well-being most statistically significant are stress (p&lt;0.001) and the interaction of feng shui and bedroom rating (p&lt;0.001). Positive feng shui impact is highest for participants without stress and low satisfaction with the bedroom environment.&#x0D; &#x0D; &#x0D;

Effects of window opening on the bedroom environment and resulting sleep quality

The effects of two window states (closed or open) on the bedroom environment and on sleep quality were investigated. Twenty-seven subjects (14 males and 13 females, 20–33 years old) without sleep disorders and chronic diseases participated. The subjects slept for two consecutive nights with windows open and two consecutive nights with windows closed in four dormitory rooms adapted for the purpose of this study, one person at a time. The order of exposure was balanced among participants. Bed temperature, room temperature, relative humidity (RH), carbon dioxide (CO2), particles (PM2.5), and noise were monitored during sleep. Sleep quality was measured using subjective ratings, a wrist-worn sleep tracker, and (for one group of 14 subjects only) polysomnography (PSG) for home use; snoring in this sub-group and awakenings were also registered. Higher PM2.5 and noise levels were found with windows open, while higher room temperature, RH, and CO2 levels were measured with windows closed. There were no differences between conditions in terms of objectively measured sleep stages but the subjects with the PSG attached snored significantly less and woke up significantly less often when sleeping with windows open. Start sleep time, end sleep time, total sleep time (TST) and time in bed (TIB) measured with the sleep tracker were confirmed by the measurements made using PSG, light sleep (N1 + N2) and sleep latency were in moderate agreement but there was no significant agreement for REM and deep sleep (N3). When sleeping with windows open, the subjects rated the air as fresher but reported higher noise levels, feeling less rested, a worse mental state and well-being, and their replies on the Groningen sleep quality scale indicated poorer sleep quality. There was no clear association between the performance test score and sleep quality. These results suggest that sleeping with windows open can provide some benefits by increasing ventilation with outdoor air, reducing CO2 concentrations, improving air quality as indicated by the subjectively rated air freshness and some of the parameters defining sleep quality, but it may also result in some discomfort if there are episodic loud noise events outdoors. Further studies are required to clarify the role of open windows in achieving good sleep quality.